Spark plug



Aug. 28, 192s. 1,681,997

.H. MUNRoE SPARK PLUG l :Filed Sept. 4, 1926 Patented Aug. 2s, 192s.

UNITED` s'ATEs O HARRY MUNROE, OF NEW YORK, N. Y.

SPARK PLUG.

Application led September 4, 1926. Serial No. 133,616.

This invention relates to spark plugs for internal combustion engines.

An object of the invention is to provide a spark plug for use with internal combustion engines which is so constructed that it can easily and quickly be inserted in and removed from its operative position in the internal combustion engine.

Another object of the invention is to pr'ovide a spark plug which can be quickly removed from its position in the internal combustion engine without the use of tools.

A further obj ect of the invention is to provide such a spark plug which has a gas tight lit with the internal'combustion engine.

Other objects and advantages of the invention will appear from the following description taken in connection with the accompanying drawings which illustrate by way of eX- ample a preferred vembodiment'of the invention and in which l Figure 1 is a side elevation of a spark plug and carrier therefor, v

\ Figure 2 is a centralvertical sectional viewl of the structure shown in Figure 1,

Figure 3 is a side elevation of the retaining bushing,

Figure 4 is a side elevation of one of the gaskets, and,

Figure 5 is a side elevation of a slightly modied form of my invention.

Referring in detail to the drawings, the reference numeral 1 indicates the spark plug carrier or container which, as shown. may comprise the substantially cylindrical and hollow body portion 2, having the reduced lower end 3 externally-screw threaded for engagement with the internal screw threads provided in the internal combustion engine for the reception of a spark plug.. Depending from the reduced lower endy 3 and .bent substantially at right angles in the usual manner is the outer electrode 4.

Above its central portion the spark plug carrier is provided with laterally extending wings 5 by which the spark plug carrier may be grasped manually and rotated to eiect 1ts removal from or insertion in an internal combustion engine.

The carrier 1 is formed hollow, as stated, for the reception of a spark plug proper` which may consist of an insulator 6 formed of porcelain, or other suitable or desirable material. The central portion of the spark plug proper is made to lit easily within the carrier and is beveled inwardly, as shown at 7 and 8, toward reduced ends 9 and 10. The end 10 is tapered and has projecting through 1t the center electrode 11 lying adjacent to, but spacedfrom, the outer electrode 4. Atits other end the center' electrode 11 is threaded for the reception of the usual knurled thumb nuts 12 and 13 for retaining thereon the lead lterminal froml the Jsparking system in the usual-manner.

The spark plug carrier 1 is interiorly beveled at 14 to conform to the bevel 8 provided on the porcelain body, and between the two beveled portions is inserted a beveled gasket 15 which may' be of copper or of asbestos or of a combination of copper and asbestos or other suitable material. A. Similar gasket 16 contact with the top of the bevel gasket 16,

and the retaining bushing thereby locksthe porcelain body within the carrier.

`'is placed upon theupper bevel 7 on the por- The wings 5 are preferably provided with openings 23 which permit proper air circulation, and the threads of the extension 3 terminate short of the top andbottom of the eX- tension as shown in order to guide the eXtension into the openings and to insure a tight fit between the lower end of the body 2 and the internal combustion engine.

The body 2 is provided with an annular groove 21 arranged below the wings. The body, above the groove 21 is covered with a layer of asbestos or other fire-proof materialv which is pressed thereon'7 the lire-proof material terminating at the groove 21 into which it is pressed to form a head 22 at its lower end. `The fire-proof layer covers the wings 5. as well as the body 2 and is cut away to leave the apertures 23 open. Thisasbestos covering allows the wings and carrier to be handled without danger of burning the hands.

In the modification shown in Figure 5 the wings 5f are arranged substantially vertically and consequently` do not extend laterally to any great extent'. This form is for use where no greatamountof room. is available djue te CJI pet-cocks, studs, or the like being arranged adjacent the plug openings.

It Will thus be seen that by the foregoing Construction there has been provided a spark plug which can easily and quickly b e inserted inand removed from its operative position in an internal combustion engine; that screw threads are provided only on the carrier and the retaining bushing; that the spark plug proper has a gas tight lit Within the-carrier; and that the porcelain body may be readily removed from the carrier by taking off theretaining Washer, and the carrier together Wit-h the porcelain body may be unscrewed manually Without the use of any tools, by rotating the carrier by means of the laterally extending Wings.

What is claimed is:

1. A spark plug comprising a screw threaded carrier, a fire-proof fibrous layer arranged about said carrier, an insulating body arranged in said carrier, and means to retain said insulating body in the carrier.

2. A spark plug comprising a screw threaded carrier having an encircling groove, an

asbestos layer pressed into Said groove and surrounding the carrier above said groove, an insulating body arranged Within said carrier, and means to retain said body Within the Carrier. V

3. A spark plug comprising a screw threaded carrier having an encircling groove, an asbestos layer pressed into said groove and covering the carrier above the groove, a porcelain body freely insertable in said carrier, a threaded retaining bushing in said carrier abutting said porcelain body, and lateral perforated Wings on said carrier for effecting manual rotation thereof, said Wings being covered by the asbestos layer.

4. A spark plug comprising a screw threaded carrier, and a fire-proof fibrous layer -arranged about a portion of the carrier.

5. A spark plug Comprising a screw threaded carrier, lateral Wings on said carrier, and an asbestos layer arranged about a portion of the carrier and the Wings.

In testimony whereof I aliix my signature.

HARRY MUNROE. 

